How To Fix a Leaking Toilet

Updated: Apr. 21, 2024

If your toilet is showing signs of a leak around the base, chances are you have an issue with the wax seal or flange.

Next Project

3 - 4 Hours




Under $20


Are you noticing mysterious puddles at the base of your toilet? What about water stains on the ceiling of the room below your bathroom, or an occasional smell of sewer? All these signs point to a possible leak around the toilet flange — the metal or plastic ring that connects the toilet to the waste pipe.

Toilet leaks typically occur in one of two ways: clean water dripping from the tank, or dirty water seeping out through the bottom and saturating the flooring. If you see signs of leakage from beneath the toilet, fix it without delay. Small leaks trapped beneath the toilet will eventually rot floor surfaces. Wait too long and repair costs rise, especially if the rot reaches the subfloor or floor joists.

Luckily, it's not difficult to pull and reset a toilet, and doing so can teach you a great deal about how the toilet itself functions. We'll share tips on pulling the toilet as well as how to diagnose and fix common causes of leaks. Finally, we'll show you how to reset the toilet.

When To Call a Pro

If the pipe itself is cracked, or if you need to repair the toilet quickly (say, if it's the only toilet in the home), then you're probably better off hiring a pro.

Tools Required

  • Caulk gun
  • Hacksaw
  • Pliers or adjustable wrench
  • Putty knife
  • Wet/Dry vacuum or sponge

Materials Required

  • Plastic toilet shims (optional)
  • Rag
  • Silicone caulk
  • Towels
  • Wax toilet ring and bolts

Project step-by-step (10)

Step 1

Turn off the water supply

  • Typically, there’s a water shut off valve near the base of the toilet.
  • Turn the control handle to the right to shut off the water supply.
    • Some valves need to be turned repeatedly, while others only take a quarter turn.
  • If there’s no shut off near the toilet or if the shut off won’t close completely, turn off the main water supply.

Turning off the water supplyDan Stout for Family Handyman

Step 2

Drain water from the toilet

  • Flush the toilet and hold the handle down to drain out as much water as possible.
    • Because the water supply is off, it will drain without refilling the tank.
    • This will remove most of the water, but not all.
  • Use a wet/dry vacuum or a sponge to remove the last of the water.
    • While the water in the tank is clean, the water in the bowl and trap definitely isn’t. Wash your hands as needed.
  • Disconnect the water supply line from the toilet tank.
    • Have paper towels or rags on hand for any water that leaks out the fill valve.

Draining the waterDan Stout for Family Handyman

Step 3

Pull the toilet

  • Remove the toilet seat and set it aside.
  • Remove the bolt caps, then the nuts that secure the toilet to the floor.
    • If the bolt spins along with the nut, grab the exposed bolt above the nut with locking pliers.
    • Loosen the nut just enough to squeeze in a hacksaw blade below the nut and saw through the bolt.
  • Lift the toilet high enough to clear the bolts (about three or four inches) and set it aside.
    • Lift with your legs rather than your back.
    • If the toilet is too heavy, disconnect the tank from the base and remove each half separately.
  • Stuff a rag into the drain line to keep sewer gases contained.
    • Use a rag that’s about the size of a small hand towel. You do not want the rag to fall into the waste pipe. (Trust me on this one.)
    • Note: Some of the photo details were obscured with the rag in place, so for the sake of clarity I removed the rag blocking the toilet hole. Keep the rag in place on your own project,

Pulling the toilet seatDan Stout for Family Handyman

Step 4

Scrape wax from flange and toilet

  • Scrape all the old wax from the bottom of the toilet and toilet flange with a putty knife.
  • If the toilet was caulked to the floor, scrape off any stuck-on caulk.

Scraping the wax from under the toiletDan Stout for Family Handyman

Step 5

Identify the cause of the leak

This step will be unique to your situation. Sometimes the issue is immediately apparent. Other times, it takes more investigation.

In the toilet I was repairing, it turned out that whoever installed the bathroom flooring hadn’t leveled the floor around the toilet flange. Rather than take time to fix their mistake, they’d simply left a handful of tile spaces and hoped things would be OK. This poor fix allowed the toilet to rock, which over time pushed the wax seal out of alignment and caused a leak.

Here are some common causes of leaks around the flange:

  • Broken flange.
    • Identified by a crack in the flange, usually on the outside of the slot that holds the toilet bolt.
    • Most common with cast iron or plastic flanges.
    • Repair with a flange reinforcement ring.
  • A flange that’s too low.
    • Flanges that sit more than 1/4-inch below the finished floor can have this problem.
    • Common when a non-plumber installs a new floor, and doesn’t understand the importance of a good seal at the flange.
    • Repair with a flange extender.
  • Wax ring failure.
    • A wax ring won’t deteriorate, but it can be pushed down, squeezed to one side or twisted out of place by a loose, wobbling toilet.
    • If nothing appears to be wrong, resetting the toilet with a new wax ring might be the only thing you need to do.
    • This is the most common problem when toilets leak at the base. Luckily, it’s also the easiest solution.

Identifying the issues Dan Stout for Family Handyman

Step 6

Repair the issue

Once you’ve identified the root issue, it’s time to fix it.

  • Repair broken flanges with a flange reinforcement ring.
  • Repair low flanges with a flange extender.
  • Repair damaged wax rings by replacing the ring and stabilizing the toilet to prevent repeat issues.
    • In my case, I added another vinyl tile to level the flooring beneath the toilet.
  • If the flooring is still wet from the leak, clean it up and dry it thoroughly.
    • Leave a fan on it to speed this process.
  • If the leak has gone on for a long time, the flooring or subfloor may be damaged. Remove any rotten or weakened material and replace it.
    • If the subfloor or joists are rotten, this will take some carpentry skills. If you’re not comfortable with that type of work, it’s best to bring in a pro.

Repairing the issueDan Stout for Family Handyman

Step 7

Install the new wax ring

  • Place the toilet bolts in the flange.
    • The wide bottom of the bolt fits in the wide opening of the flange, then slides into place.
    • Note that these new bolts are taller than the ones you removed. This is to make installation easier. You’ll trim them down to size after setting the toilet.
  • If the bolts came with plastic washers, slip them over the bolts so they fit snugly against the top of the flange.
    • These will keep the bolts upright and in place while you set the toilet.
    • If you haven’t already removed the rag, be sure to do so now.
  • Set the wax ring in place.
    • If you have a “reinforced” wax ring with a plastic spout, it’s usually easiest to set it onto the flange opening.
    • If you have a plain wax ring, it’s usually easiest to set it around the spout on the bottom of the toilet.
    • I recommend the reinforced rings. They’re an extra layer of protection for only a few dollars more.

Installing new wax ringDan Stout for Family Handyman

Step 8

Set the toilet

  • Lift the toilet high enough to clear the bolts.
    • Remember, the new bolts are taller than the ones you removed.
  • Set the toilet down as straight as possible. You want to avoid knocking the wax ring out of center.
    • You may not get it perfectly straight and even. That’s fine, as long as you don’t damage the wax seal.
  • Rock the toilet back and forth gently, pushing the wax tight.
    • Don’t twist the toilet into place, which can create a void in the wax seal.
  • Put the washers and nuts on the toilet bolts.
    • Hand-tighten both sides, then switch to pliers or a wrench.
  • Alternate from one side to the other so the toilet is tightened with uniform pressure.
  • Tighten each side slightly, then rock the toilet. If it’s loose, continue tightening until it sits tight and even against the floor.
  • Do not over-tighten. Tightening too much can crack the porcelain.
  • Snap off the top of the bolts to bring them down to the right height.
  • Use pliers for this, or a hacksaw to cut through and pliers to finish the job.
  • Replace the toilet bolt caps.
  • Replace the toilet seat.

Setting the new toilet seat on floorDan Stout for Family Handyman

Step 9

Reconnect water supply

  • Connect the water supply to the fill valve on the toilet tank.
  • Hand-tighten the supply line.
    • You should not need pliers to tighten the supply line. If you do, there is a good chance you will strip the plastic threads.

Reconnecting the water supply to toilet Dan Stout for Family Handyman

Step 10

Test and adjust as needed

  • Flush the toilet and allow it to fill up. Look for leaks around the water supply, tank and base.
  • Sit on the toilet a few times and move from side to side. If it rocks or shifts, tighten the bolts further or put a shim in place.
  • Once the toilet is definitely tight, stable and running without leaks, caulk the gap between the toilet and floor.
    • How much needs to be caulked depends on the code requirements where you live. Some areas require caulk all around the toilet. Others allow a gap in the back, while a few do not require caulk at all.

Testing the new toilet seatDan Stout for Family Handyman